"To help marketers build better campaigns, Facebook offers aggregated insights to managed clients that help them understand trends about their fan bases," a spokeswoman for the company told The Times in an emailed statement. "These tools do not provide marketers with any data about their competitors' fan bases."

The tool is only available internally, and Facebook is making marketers come to its offices to access it, according to AdWeek.

Companies could find the tool useful for putting together marketing campaigns. As AdWeek points out, the tool could help companies decide which TV show to advertise on or which song to use in a commercial.

Fortunately for Facebook users, though, the company said it is not giving out data about specific users to companies.

"As always, Facebook does not share user-specific data with advertisers," the spokeswoman said.

Facebook has not said whether it plans to offer the tool to all its advertising clients, but it could prove to be another valuable source of revenue for the social network if it does.

[Update 6:39 p.m., Oct. 17: A spokeswoman for Facebook said managed clients are not higher priority than other clients but they do work with Facebook sale representatives.]